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Finding the Fourth Proportional to 391.75, 540.62 and 217.11

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Solution

The fourth proportional to 391.75, 540.62 and 217.11 is: 299.61

Step by Step Solution

  1. Step 1: Write the proportion equation
    391.75 : 540.62 = 217.11 : x
  2. Step 2: Convert to fraction form
    391.75/540.62 = 217.11/x
  3. Step 3: Cross multiply
    391.75x = 540.62 × 217.11
  4. Step 4: Simplify right side
    391.75x = 117,374.01
  5. Step 5: Solve for x
    x = 117,374.01/391.75
  6. Step 6: Final answer
    x = 299.61

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Why These Related Problems?

These problems maintain the same ratio (1.38) or explore similar proportional relationships. Practicing with related ratios helps build understanding of proportional relationships.